Method and apparatus for maintaining multi-component sample gas constituents in vapor phase during sample extraction and cooling

Abstract

An apparatus and method for diluting and cooling that is extracted from high temperature and / or high pressure industrial processes. Through a feedback process, a specialized, CFD-modeled dilution cooler is employed along with real-time estimations of the point at which condensation will occur within the dilution cooler to define a level of dilution and diluted gas temperature that results in a gas that can be conveyed to standard gas analyzers that contains no condensed hydrocarbon compounds or condensed moisture.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This application claims the benefit of Provisional U.S. patent application Ser. No. 60 / 564,320 filed 22 Apr. 2004.[0002]The U.S. Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of Contract No. DE-FC36-03G0 13175 awarded by the U.S. Department of Energy.BACKGROUND OF THE INVENTION[0003]1. Field of the Invention[0004]This invention relates to a method and apparatus for maintaining multi-component sample gas constituents of a gaseous process stream in vapor phase so as to enable on-line characterization of these streams. More particularly, this invention relates to a method and apparatus for reducing the pressure and / or temperature of a stream extracted from a high pressure and / or high temperature industrial process so that condensable constituents in the unconditioned gas stream remain in the vapor phase an...

AI Technical Summary

Benefits of technology

Enables real-time, condensate-free evaluation of high-temperature and high-pressure industrial processes, improving process efficiency and economy by avoiding condensation and maintaining accurate sample representation.

Problems solved by technology

For some applications, difficulties and uncertainties in modifying the sample streams to conditions acceptable to on-line analyzers result in reliance on batch analyses performed on purposely condensed samples that are collected for remote laboratory analysis.

Although batch sampling followed by remote analysis is often a simpler approach, results are delayed, and in cases where portions of the collected sample may be lost or chemically altered during collection, storage, and laboratory analysis procedures, this approach also may not be quantitatively or qualitatively accurate.

The inherent weakness in this approach for syngas conditioning emerges when the gas is cooled to a temperature that is below the local dew point of one or more of its constituents (the dew points of water and hydrocarbon vapors are primarily determined by their local partial pressure within a heat exchanger).

This condensation can degrade the efficiency of the heat exchanger, create cleanup, maintenance, and health issues, and provide the opportunity for free radicals in the condensed vapors to react and change in structure and concentration before analyses can be carried out.

These tars and oils can also be challenging to remove from sample lines and traps.

As previously indicated, depending on the process and the analytical instruments used to characterize the process, the loss of vapor-phase constituents by condensation can result in plugged sample lines, delayed or inaccurate measurements, and failure of the gas analyzers.

For this reason, syngas analyses have generally been limited to batch sample extraction methods that include built-in traps or reservoirs for collecting condensed hydrocarbons.

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